SARS-CoV-2(25) COVID-19(22) Donor(20) convalescent plasma(20) Blood(15) material(15) plasma(12) blood donor(11) antibody(11) IgG(11) Blood donors(10) collected(9) Blood safety(9) titre(9) Infection(8) Characteristics(8) country(8) healthy(8) Immunoglobulin(8) transfusion(8) vaccination(8) Neutralizing activity(7) convalescent(7) Seroprevalence(7) IgM(7) Neutralizing(7) neutralizing antibody(7) reduced(7) COVID-19 pandemic(7) COVID‐19(6)